Serotonin (5-hydroxytryptamine or 5-HT) is a neurotransmitter implicated in the etiology or treatment of many medical problems, including anxiety, depression, schizophrenia, hypertension, stroke, migraine, nausea and cognitive deficits. A particular 5-HT receptor in the central nervous system classified as the 5-HT.sub.1a receptor has been widely implicated in anxiety and depression. A class of compounds containing the arylpiperazine group bind with the 5-HT.sub.1a receptor and have anxiolytic and antidepressant properties in man (Annual Reports in Medicinal Chemistry 27, 21-22 (1992). Buspirone, shown below, is a clinically effective anxiolytic agent. ##STR3##
Bagli et al., J. Med. Chem. 27,875-881 (1984) discloses 1-(2-troponyl)piperazine derivatives which have dopaminergic activity.